Apparatus for and method of cementing oil-well casings



July V22 1924. v 1,502,179

E. v. CROWELL APPARATUS FOR AND METHOD OF CEMENTING OIL WELL CASINGS Filed June 15 1920 Q 4 @Kerman A TTUR/VEYS' Tamika ...iuiy 22, 1924.

ERD V. CROWELL, F TULSA, OKLAHOMA.

APPARATUS FOR AND METHOD OF CEMENTING OIL-WELL CASINGS.

HEISSUED Application led June 15, l192C). Serial No. 889,151'.

To all whom t may concern.'

Be it known that I, ERD V. CROWELL, a citizen of the United States, and a resident of Tulsa in the county of Tulsa and State of Oklahoma, have invented certain new and useful Improvements in Apparatus for and Methods of Cementing Oil-Well Casings, of which the following is a specificaj tion.

My invention relates to improvements in well casings, particularly those of the type employed in oil and gas wells, and it consists in the constructions, combinations and arrangements herein described and claimed.

Oneof the objects of the invention is to provide acementing shoe for use in connection with an oil or gas well casing, by means of which a cementing mixture, as for example mud-Huid, can be ejected from the lowermost section or oil string to fill the space between the oil string and well bore and thus seal the formation seat against the seepage of water.

A further object of the invention is to provide a cementing shoe for oil or' gas well casings, which offers the distinctive and eX- clusive advantage of providing means for placing a cementing mixture behind the oil string while the well is expelling oiland gas and the casing is resting"on its formation seat.

A further object of the invention is to provide means for introducing a cementing mixture into the space between the oil string and wall of the hole, without having to first plug the hole beneath the casing, raise the casing or work against the high pressure of the oil and gas.

, A further object of the invention is to provide means in oil or gas well constructions, enabling the making of a water-tight seal between the casing and rock formation independently of the casing shoe on the lowermost extremity of the oil string or the texture of the landing formation on which the shoe rests.

A further and important object of the invention is to provide a valve mechanism forming part of the well casin throu h which the mud-Huid is ejected ehind't e casing. i

A further object of the invention is to provide a construction by means of which the cementing material may be introduced around the casing while the latter rests on its formation seat before the oil or gas sand has been opened, the entire casing bein employed in carrying out this mode o operation.

Another object of the invention is to' adopt a method of carrying out the foregoing objects.

Other objects of my invention will appearv in the following specification reference being had to the accompanying drawings, in which: Figure 1. is a longitudinal section illustrating the improved cementing apparatus wherein the whole casing is emp oyed in discharging the cementing materia and Figure 2 is a detail section of the same structure.

This application is principally concerned with that form of the invention wherein the entire casin tion 'of disc arging the cementing material, another apparatus for the same purpose bein disclosed in my Patent #1,432,017, Octoer 17, 1922, which is a division of this application.

In order that the reader might be able to more fully appreciate the purpose of the invention, it is thought well to preface the description of the construction and mode of operation by a brief description of oil well casing operation. Casing, as now used in oil field operations is ,either iron or steel tubular pipe, the kinds` and sizes thereof differing considerably in various fields, all

according to the peculiar conditions encountere n A complete column of ipe or casing as placed in the bore of o1 wells, is com- 'monly referred to as the string of casingl.

The fundamental purpose of the oil we casing is that of protection, that is to say,

to keep the water and other foreign substances from falling into tlie shot hole at the bottom and thereby either crowding the oil back from the bore or obstructing the lower end of the bore in such a manner that neither oil no r gas can flow.

is employed during the operasist of alternating layers of lime-stone,

- the sand layers in the same manner.

' In drilling oil or gas wells, the formations passed through asthe depth increases conshale, and occasionally a stratum of sand. The shale layers predominate over the lime layers as regards number and thickness, and again, the lime layers predominate over Usually the underground water finds itschannels offlow in the lime or sand strata, the water flowing through the sand stratum generally above or below a lime stratum.

As the depth ofthe hole is increased during the drilling operation, water producing lime, or sand strata are encountered, the

\ I water thus released by the puncturing of the strata by the drill point, settlingin the hole and filling it with water. The drilling operations are thus greatly retarded, due to the cushioning eHect the water has on the drilling operation of the-tools.

Again, the water released from the lime strata washes ldown over the shale strata below, causing the shale to cave, slough out and fall down the hole. A loose shale formation may thus cave to such an extent as to even entirely bury the tools. An enormous amount of additional work is required` in thereafter excavating the material and recovering the tools.

With this brief survey in mind, the need for the improvement which the invention offers will be understood. The invention relates to a construction by which the sealing of a casing in a bore is performed before the.

- oil or gas stratum has been opened.l The o-il string comprises several casing sections la, whlch occupy a substantially central position in the well bore B, the casing shoe 2 at the .lowermost extremity resting on an annular projection of rock or other material, commonly known as the formation seat S. The bore of the well is ultimately intended to communicate with what is known as the l shot hole (not shown).but according to the invention the bore is cemented before such communication is established.

bottom of thebore B. This ltubing has a belt of perforations 35 out of which fluid ows into the casing 1a in accordance with the arrow, completely illingthe inside of the casing and escaping through the ports The casing 1a is let down into the bore until the shoe engages vand rests upon the formation S. The cementing shoe 3a is introduced in the casing l at the desired location from the bottom, the mud liuid outlet valve 7 being normally held closed vby the leaf springs mentioned. The tubing 25 with its packer mechanisms 36 is lowered into the casing until it strikes the closed bottom of the bore.

Mud liuid or other cementing material is then introduced into the tubing 25a whence it escapes at the perforations 35. Thecasing la-lls upto the packers 36 the pressure of subsequently inowing cement forcing the valves 7 a open so that the bore -becomes lled as shown. The injector tubing 25 is withdrawn while the cement inside the casing is yet plastic. The cement inside the casing may be removed by suitable means, but that outside of the casing remains in place.

I claim l j l. Means for sealing a well before opening the bore into a productive stratum, comprising a well casing adapted *to rest on the formation seat of the bore,- with a plurality of valved ports; and tubing let down in the casing, with packing means for securing a joint therebetween and the casing, havin perforations through which sealing materia is ejected to fillthe casing vup to the packing means, and then escape throughv said ports to fill the surrounding bore.

2. Means for sealing a well before opening the bore into a productive stratum, comprising a ,well lcasing adapted to Test on the formation seat of the bore, composed of sections and including a ported cementing shoe; tubing let down in the casing, having openings through which sealing materialis ejected into the casing; and valves controlling the port, enabling the material to flow out of the casing into the bore but not back.

3. The method of sealing a well consisting of lowering a casing with an opening into the bore of a well and resting itl permanently on the formation seat, inserting a cement injector into the casing until it strikes the bottom of the bore, introducing cement by said injector into the inside of the casing until it reaches and flows through the opening and into the bore, withdrawing the injector while the cement is yet plastic, and preventingv the return of the cement from the bore through said opening.

, neom'm 4. The methodo sealing va. wel] consisting olowering a casing with an opening into the bore of a well aindrest'ing 1t permanently on the formation seat, inserting 5 a perforated cement injector into the casing until it too rests on the formation seat, introducing cement into said 'injector causing it to How out of said erforation into the casing thence through t e opening and into the bore, withdrawing the cement is yet plastlc, and preventing the return of the cement from the bore through said opening.

ERD V. CROLL.

the injector While '10 *i 

